Mini-SONG&Site testing at DelinghaLicaiDengSONG&mini-SONG
Mini-SONG & Site testing at Delingha Licai Deng SONG & mini-SONG
PrimaryScienceGoalsPhotometry of asample(defined later)ofopenclustersbasic physical parametersmeasuredinauniformway;Timedomainstudy of variableobjectsinselectedclusters:Iongtime based line,high cadence and high duty cycle,highprecisionphotometricobservations; A completesurvey(definedlater)ofstellarvariabilities alongthemain sequence(Scu,βCep&yDor etc.....)inselectedopenclustersc Acompletesurvey(definedlater)ofsmallandlargeamplituderedvariablesalongtheRGBs ofselectedopenclusters;Acompletesurvey(defined later)ofeclipsingbinaries in selectedclustersc Lookingfortransitofexoplanet systemsLookingforflaretypevariabilities inselectedclusters StellarrotationandspotsactivitiesRTime domainstudy of selected fieldareas;
Primary Science Goals ❖ Photometry of a sample (defined later) of open clusters basic physical parameters measured in a uniform way; ❖ Time domain study of variable objects in selected clusters: long time based line, high cadence and high duty cycle, high precision photometric observations; A complete survey (defined later) of stellar variabilities along the main sequence ( Scu, Cep & Dor etc.) in selected open clusters; A complete survey (defined later) of small and large amplitude red variables along the RGBs of selected open clusters; A complete survey (defined later) of eclipsing binaries in selected clusters; Looking for transit of exoplanet systems; Looking for flare type variabilities in selected clusters; Stellar rotation and spots activities; . ❖ Time domain study of selected field areas;
Secondary science goalsImmediatefollow-up ofthe opticalafterglowsofGRBs;Follow-up of SNsfound in nearbygalaxies;OthergenericToO
Secondary science goals: ❖ Immediate follow-up of the optical after glows of GRBs; ❖ Follow-up of SNs found in nearby galaxies; ❖ Other generic ToO;
FundamentalrequirementsonhardwareTorealizelongtimebaselineand cadence,amini-SONGtelescopeshouldbeattachedtoeachSONGnode,atleastinSONG-NorthTorealizeoursciencegoals,(simultaneous)2color(SDssg,r)photometrysystemisneeded;TocoverlargeenoughclusterandvicinityareaofGalacticopenclusters,especiallythewellstudiedoldpopulationsofclusters,suchasM67,NGC188,NGC7789etc.,aminimumof40'x40'FOVisneededToreachthelowerlimitof -Scutistripoftypicalopenclusters,andtohavethemobservedat100olevelS/N,and1mmaccuracyata-300sexposure,aminimumapertureof50cmisneeded(tobedetermined)Togetanidealsampling,4kx4kCcD(s)isneeded;
Fundamental requirements on hardware ❖ To realize long time base line and cadence, a mini-SONG telescope should be attached to each SONG node, at least in SONG-North; ❖ To realize our science goals, (simultaneous) 2 color (SDSS g, r) photometry system is needed; ❖ To cover large enough cluster and vicinity area of Galactic open clusters, especially the well studied old populations of clusters, such as M67, NGC188, NGC7789 etc., a minimum of 40’x40’ FOV is needed; ❖ To reach the lower limit of -Scuti strip of typical open clusters, and to have them observed at 100 level S/N, and 1mm accuracy at a ~300s exposure, a minimum aperture of 50cm is needed (to be determined); ❖ To get an ideal sampling, 4kx4k CCD(s) is needed;
Basics of the survey:Thesampleofclustersaredefinedinsuchawaythatthesize(dynamicalradius)rangesin10-30'(tobedetermined),andthelowerlimitofo-Scutistriplocatesat19m(ifexist,foroldclustersor5mbelowtheMSTOarecovered;Apilotgeneralsurveyforpre-selectedsampleofclustersmeasurethebasicphysicalparameters;Differentialphotometrywillbeadoptedthoughouttheprojecthowever,calibrationshouldbedonefromtimeto timeduringthesurvey;Thenumberofclusterseventuallyto beobservedaresimilartothenumberof SONGprogramstars,sothatthecadenceanddutycyclekeepthesameastheSONG;
Basics of the survey: ❖ The sample of clusters are defined in such a way that the size (dynamical radius) ranges in 10’-30’ (to be determined), and the lower limit of -Scuti strip locates at 19m (if exist, for old clusters) or 5m below the MSTO are covered; ❖ A pilot general survey for pre-selected sample of clusters, measure the basic physical parameters; ❖ Differential photometry will be adopted though out the project, however, calibration should be done from time to time during the survey; ❖ The number of clusters eventually to be observed are similar to the number of SONG program stars, so that the cadence and duty cycle keep the same as the SONG;